6 Volt or 8 Volt...Will it Work Without Damage

Hellerlj

Member
Was having a discussion with a friend, we were tossing
about how hard a 6volt V8 is to start sometimes, he mentioned
that he had seen people install an 8volt Tractor Battery in place
of the stock 6volt, and said that it spun the engine a bit faster,
and would have NO bad effects on the rest of the system.....
True ?? False?? BS???

Has anyone out there had experience with doing this, or
knows the Pros and Cons ????

Any and All feedback is much appreciated

Les in Minneapolis
 
A 6 volt system in good shape will start and function fine. I have two of them and wouldn't change. 8 volt batteries are ony a band aid and not recomended,they only cause more problems. you need good heavy battery cables, good wiring connections, and a good battery as well as a good charging system. Optima 6volt batteries are the best. all of this will cost but you will have a great 6 volt system.
 
I have had enough experience with 6 volt flathead V8s not starting in the Minnesota winter to never criticize someone who wants to switch to a higher voltage. I have never measured it but the starter grabs so much power that the spark has to suffer. I don't know if the 8 volts would burn out things like the gauges but another two volts shouldn't push the specs too much, at least not as much as the 12 volt would.
The thing I am not sure about is if the 6 volt generator will adequately charge the 8 volt battery. I have heard though that the 6 volt generator will charge whatever is required, including a 12 volt battery, so there are differing opinions on that. Best to check with a generator repair shop to see if that is true.
 
what did people do when a 6 volt car was new, in very cold climate? i have a 6 volt battery with a fresh motor and it cranks right up , no trouble
Brendan
 
I have had enough experience with 6 volt flathead V8s not starting in the Minnesota winter to never criticize someone who wants to switch to a higher voltage. I have never measured it but the starter grabs so much power that the spark has to suffer. I don't know if the 8 volts would burn out things like the gauges but another two volts shouldn't push the specs too much, at least not as much as the 12 volt would.
The thing I am not sure about is if the 6 volt generator will adequately charge the 8 volt battery. I have heard though that the 6 volt generator will charge whatever is required, including a 12 volt battery, so there are differing opinions on that. Best to check with a generator repair shop to see if that is true.

Good point about the 6V gen. being able to charge an 8 V. battery. It would seem that the regulator would have to be readjusted otherwise the 8 volt battery will not reach "full charge." Generally speaking switching to an 8 v. battery is a waste of time and money and not a solution to the problem.
 
what did people do when a 6 volt car was new, in very cold climate? i have a 6 volt battery with a fresh motor and it cranks right up , no trouble
Brendan

We had a '40 Ford when I was growing up in MN in the 1940's and 1950's, and my father had a job that required a dependable car (he was a pilot for NWA). Frankly, I never remember any particular starting problems with the car. Nor do I remember any overheating problems, except once in 1948 when we were driving back from my grandparents' home in IA into extremely strong headwinds that we later learned were the remnants of a tornado. Dad might disagree if he were still here, but my overall recollection is that the car was mostly trouble-free and ran good.

scan_4520173721_1-1.jpg
 
Don't forget your increasing the voltage by 20% -+ on your ignition system and your electrical componets. If everything being brand new it would handle it. The resistor on the ignition reduces the voltage to 4 volts to reduce the wear, so that will shorten the life of the points. The generator tries to put out greater that 6 volts, but will the regulator handle the increase. It seems, at least by me everytime I deviate from Henry I just stepped in a pile of do-do. To improve your system bring your electrical wiring and connections up to date and you'll save yourself from a lot of aggravtion.
 
jdl, is your Optima a resent purchase? Heard some tails about them. I'm looking into using one myself.
 
In the 40's it was a common practice in Ohio to use 8 volt batteries in the Fords. My father had a trucking company in the 40's and ran 8 volt batteries in all his trucks, so they would start in cold weather and when the engines were hot. I am sad to say he is no longer here to ask if he had to adjust the voltage regulator, but he had no trouble with generators. Marv
 
Old Willys Jeeps were the only ones I remember working on regulary that had an 8-volt system but they had matching elecrtical & charging system components too. I think the regulated voltage was 8.5 to 9-volts. One step above a 6-volt system. An 8-volt battery will work in every respect but will suffer on charge rate when used in a stock 6-volt system. The only item in the old cars that might have a problem with the increased voltage would be a radio if one is installed. Those old radio sets were very sensitive to polarity and voltage rating.
 
Last edited:
jdl, is your Optima a resent purchase? Heard some tails about them. I'm looking into using one myself.

One of my Optima batts. is 6yrs. old and still going strong, the other is only 3 mos. old, the newer one has a little thicker top cover that makes the overall highth a little taller. both fit in the Ford script case but the on the newer one the posts set a little lower but still fits o.k. I made my own case's from Ford script cases by gutting them and cutting out the bottom and making the top piece. it would be a lot eaiser to buy the one that is already done. (expensive)
 
I lived in Eastern Idaho when I purchased my '36 Ford. With Idaho's winter temps hovering around -30 fr. it was very common to have to push the EFV8's to get them started... The pushing vehicle was generally a stove bolt Chevy 6 clyn.
I used a 8v battery, which was located behind the seat, in my '36 Ford for many years, even after I moved to So Cal from Idaho. The 8v had no adverse effect on any of the accessories, radio, heater and gauges. The 6v regulator was adjusted to put out 9+ volts.
 
blucar, (is the photo black or blue?) my eyes are old. No problem with the fuel gauge, just a thought. When you say radio, orginal? Just asking to clarify. Someday I'll have all the answers, right now just the questions.
 
A 6 volt system in good shape will start and function fine. I have two of them and wouldn't change. 8 volt batteries are ony a band aid and not recomended,they only cause more problems. you need good heavy battery cables, good wiring connections, and a good battery as well as a good charging system. Optima 6volt batteries are the best. all of this will cost but you will have a great 6 volt system.

I agree,

I am running Optma Batteries in three of my EV8s. One has been in for more then 5 years now with no problems. I have good cables and connections and good charging systems.

One thing I have consistantly run across with other EV8s is the regulator is not adjusted correctly. It should be adjusted so you have a charging voltage of about 7 Volts when the battery is fully charged. Having the battery fully charged will do wonders for a 6 Volt system.

Also, be sure there is a ground wire run directly from the generator to the "Frame" of the regulator. Early Ford 2 brush systems did not have this feature and depended on the mounting of the regulator to the firewall and the mounting of the generator to the engine to provide a ground. The regulator needs a good ground directly to the generator to properly measure and adjust output voltage. This is often overlooked.

Chris
 
My 33 runs the 6v stock setup,and I try to trick it every time I start,I do this by just giving the starter pedal one short push,as short as posible,the engine only has to go over one compression to start ,evey time.
Lawrie
 
Some of the olld guys here ran 8vlt tractor batteries to "get a better spark" I know one that has one in a 50 Merc right now. The only change he made was to adjust the voltage regulator to charge a little more. He's my best friend's Dad. We talk flathead all the time.
 
Here's a small bit of info I found in my 49-51 Ford truck shop manual. It lists bulb life in hrs at various voltages:
voltage at source approx life in hrs
6.1.................................... 3300
6.5 .....................................1425
6.9 ......................................645
7.3 ......................................322
7.7 ......................................160
8.1 .......................................87

Quite a reduction in hrs as the voltages go up.

Barry

50 F-1
 
WOW! that's great info for what we're talking about in this thread. Great find Barry
 
Last edited:
I run an 8 volt battery as I drive it year round. I drove when we only had 6 volts. Somebody asks," what did they do when thats all they had". Well, we broke out the jumper cables mostly. Put a light bulb under the hood with a blanket over it. Took the battery in the house for the night. etc.
8 Volt works fine with a regulator adjustment. That 6 volt gen will put out much more than 8 volts. Thats why it has a voltage regulator. headlight will be a but brighter but won't last as long.
Some of the folks on here don't drive thier cars in the winter or at night so they probably are happy with 6 volts. I'll take 8 volt as an alternative to going with the 12 volt system.
 
Back
Top